Liquid crystal display devices (hereinafter abbreviated LCDs) have found widespread commercial applications in a variety of fields ranging from calculators to television sets (hereinafter abbreviated TV's) because of their excellent display performance which rivals that of the cathode ray tube, their thin and light-weight construction, and other useful features such as low power consumption. Various improvements have been made to LCD technology, and LCDs are now the most abundant type of display in use. Among such improvements, improvements in color LCD technology involve various aspects of display performance and have been particularly significant in the development of the technology.
The principle of a color display is based on a method called an “additive color mixing process.” When two or more colored light beams enter the human eye, the light beams are combined on the retina and perceived as a color different from the colored light beams. Based on this principle, any color can be obtained by additively mixing light beams of three primary colors, R (red), G (green), and B (blue), in appropriate proportions. In practice, two different systems based on this basic principle of additive color mixing are implemented in color LCD displays.
The first is a “simultaneous additive color mixing process.” To apply this system for a color LCD, three color filters of R, G, and B are used in combination with three LCD panels. Using these filters, three color images are simultaneously projected onto a screen where the color images are superimposed and merged into one color image. This idea is currently widely implemented in the mass production of modern LCDs.
The second is a field sequential color (FSC) principle based on a “successive additive color mixing process.” As shown in the diagram 100 of FIG. 1, this process utilizes the resolution limit of the human eye in the time domain. More specifically, this process utilizes the phenomenon that when successive color changes are too fast for the human eye to perceive, the persistence of the previous color causes the color to be mixed with the succeeding color, and these colors are combined and perceived as one color to the human eye. As in the simultaneous additive color mixing process, any desired color can be obtained at each pixel, so that the system achieves high image definition and also provides excellent color reproduction. The first standard color TV system utilized the field sequential method, but the method is not widely implemented in conventional mass-produced LCDs.
However, the field sequential color method based on the successive additive color mixing process has several advantages over the simultaneous additive color mixing process. First, the process of three-color filter manufacturing is very complex and expensive, whereas the manufacturing associated with the successive additive color mixing process is relatively simple and inexpensive in comparison. Second, the light transmission of a display cell in the absence of the three color filters may be three times higher, which allows for a significant reduction in power consumption using the successive additive color mixing process at the same levels of brightness and resolution for the display.
Fast switching ferroelectric liquid crystal (FLC) displays (FLCD) are good candidates for FSC LCDs, as FLCDs have been shown to have better response times than conventional nematic liquid crystals. The problems typically associated with FLCDs, such as quality of FLC alignment on sufficiently large surface area, can be effectively solved by using the photo-alignment technology described by Chigrinov et al., Photoalignment of Liquid Crystalline Materials: Physics and Applications, 248 pp., pp. 143-148, Wiley, August 2008, which is herein incorporated by reference in its entirety (hereinafter “Chigrinov on Photoalignment”).
It will be appreciated that the inventors have created the above body of information for the convenience of the reader; the foregoing is a discussion of problems discovered and/or appreciated by the inventors, and is not an attempt to review or catalog the prior art.